The purpose of any networking cable is to carry data or power from one electronic device to another. Electronic devices include but are not limited to terminals, personal computers, printers, workstations, hubs, switches, storage devices, tape drives, routers, telephone switches, and servers. Networking cables, frequently referred to, as “jumper cables”, “patch cables”, or simply “cables”, typically are multiple pair copper wires packaged in an outer flexible sheath. Networking cables are designed to interconnect an electronic device with another electronic device. Such networking cables often are used in systems where there are many networking cables connected to frames, panels, or electronic devices, each of which may have many connecting cables and which may be located closely adjacent other similar frames, panels, or electronic devices, sometimes without carefully regimented management of the cables. The connections of each cable may be remote from one another, even being in separate rooms or spaces, and the networking cables may be of substantial length.
One example of such use of networking cables is in computer centers where it is often necessary to connect a networking cable from an individual workstation at one location with another networking cable from a computer server remote from the workstation. Further the interconnections sometimes are located in crowded and/or cramped quarters. Tracing and identifying a remote connector section or end of a specific cable for changing its connection in a network or to facilitate replacement often is difficult, tedious and time consuming, and can lead to errors that create further service problems and additional costs.
Various methods and systems have been developed for locating the ends of a networking cable. One such method is a trial and error process that requires personnel to use test equipment at both ends of each and every wire pair to identify the termination points. This process may be labor intensive and expensive. The second method is a variation of the first method and involves the use of equipment to send a tone on a wire pair and then detect a particular frequency at the termination point. This process is also labor intensive. Also, to determine termination points, the cable needs to be disconnected from the computers connected to the network. As a result, these methods interfere with performance and require the workstation to be taken out of service. In addition, both systems require the test person to walk from one end of a test point to the other end. If the workstation and server are located in separate rooms or in remote locations, the previous methods are labor intensive and inefficient for easy detection of termination ends.
U.S. Pat. No. 6,577,243 to Dannenmann, et. al. describes a network cable tracing system that addresses some of these issues. Electrically activated telltales, such as light emitting diodes (LED's) are affixed to both ends of a networking cable and are activated when power is applied externally with a plug-in connection from a portable power pack. The resulting illumination of the LED's readily indicates where both ends of the networking cable are located. A system similar to this is offered by Cypress Industries, of Austin, Tex. and called the LED Cat5E RJ-45 Patch Cable. A solution of this type is useful and an improvement over some of the aforementioned labor intensive test methods. This approach has not been widely adopted though because it requires the technician to purchase a rather limited use power pack, carry it along with all of his or her other tools and individually plug it into each networking cable as part of a test protocol. Each cable also has to have a plug in connection on each end of the cable for the power pack to be attached.
An improved application is described in U.S. Pat. No. 7,221,284 to Scherer et al., which describes a self contained and self powered indicator circuit that enables tracing the location of both ends of a networked cable without the use of external test equipment, providing an indicator circuit for signaling a cable connection between two electronic devices including at least a networking cable having a plurality of conductor wire pairs encased in a flexible sheath; a connection hood on each end of the networking cable; an electrically activated telltale incorporated into each connection hood and electrically connected to at least one of the conductor wire pairs; an electric power source incorporated into at least one of the connection hoods and in electrical connection with the electrically activated telltales; and a manually operated switch incorporated into at least one of the connection hoods and in electrical connection with the electrically activated telltales.
The invention disclosed in U.S. Pat. No. 7,221,284 provided limited functionality in use. More functionality than one simple response from the manual press button is a need. In addition increased reliability demands for Cat-6 cables requires a new approach because building the increased electronics required to add the aforementioned new functionality into the confines of a cable connector which has twisted pair connections can lead to crosstalk resulting in degraded performance of the cable. In addition users desire an indicator that the electric power source is going low and a way of testing when the electric power source has lost power.